Method and apparatus for folding sheet material



F. D. MOORE Feb. 25, 1964 METHOD AND APPARATUS FOR FOLDING SHEETMATERIAL 3 Sheets-Sheet 1 Filed Aug. 10, 1962 Feb. 25, 1964 3,122,361

METHOD APPARATUS FOR FOLDING SHEET MATERIAL F. D- MOORE 3 Sheets-Sheet 2Filed Aug. 10, 1962 Feb. 25, 1964 F. D. MOORE 3,122,361

METHOD AND APPARATUS FOR FOLDING SHEET MATERIAL Filed Aug. 10, 1962 v 3Sheets-Sheet 3 United Stats atent fifice 3,122,361 METHSD AND APPARATUdFGR FGLBLJG SHEET MATERKAL D. Moore, lrving, Tera, assignor toKimberly-Clark Corporation, Neenah, Wis, a corporation of Delaware Filed Aug. 1%,1962, Ser. No. 216,252 4 Claims. (Cl. 27t}44l) My invention relates topapermaking machines and, more particularly, to devices for folding websof paper or other sheet material.

Facial tissues composed of soft, absorbent paper are generally suppliedin stacks within dispensing cartons. The tissues may be interfolded,that is, folded so that a portion of the top tissue of such a stackunderlies a portion of the tissue just beneath in the stack, and thecartons are generally provided with slots in their upper panels throughwhich the tissues may be withdrawn from the cartons one at a time. Theinterfolding causes a portion of each succeeding tissue in a stack to bepartially drawn through the carton slot, so that it protrudes therefromand is thus readily available to the user, when the top tissue is takenfrom the carton through the slot.

It is an object of the present invention to provide an improved methodand apparatus for interfolding continuous webs of facial tissue or thelike to provide a continuous stack of webs traveling in a predeterminedpath which may be severed crosswise after folding is completed, in orderto produce stacks of interfolded tissues in lengths to lit theconventional cartons above referred to. More particularly, it is anobject of the invention to provide such an improved method and apparatusin which webs are supplied from the side of the path in which thecontinuous webs travel in interfolded condition, with the method andapparatus being operative to turn the webs being supplied from the sideinto the path of the interfolded webs and at the same time to inter-foldthe new webs with folds of previously folded webs traveling in thispath.

More particularly, it is an object of the present invention to providean improved folding device having upper and lower spaced web carryingportions with folding edges on the ends of these portions extendingdiagonally of the path of Le interfolded webs. The diagonally extendingfoloing edges are such that a web carried by such a folding devicecoming from the side of this path turns around these folding edges so asto be changed in direction to travel in the path of the interfoldedwebs, and the upper and lower web carrying portions of the foldingdevice are spaced so on one or more folds of previously folded webstraveling in this path may pass between these portions whereby a fold orfolds of the new web are positioned underneath a fold or folds of thepreviously folded web or webs.

The invention consists of the novel methods and constructions to behereinafter described and claimed for carrying out the above statedobjects, and such other objects, as will be apparent from the followingdescription of a pref rred form of the invention, illustrated withreference to the accompanying drawings, wherein:

FIG. 1 is a plan view of folding apparatus embodying the principles ofthe invention and including a folding device or board for interfolding apaper web with two continuous interfolded web stacks which are drawnover the folding board;

FIG. 2 is a side elevational view of the folding apparatus;

FIG. 3 is a sectional View on an enlarged scale taken on line 33 of PEG.1;

FIGS. 4 and 5 are sectional views taken on lines 4-4 and 5-5 of FIG. 1;

FIG. 6 is a sectional view, partially schematic and on an enlargedscale, taken on line 66 of FIG. 1;

FIG. 7 is a fragmentary perspective view of the folding board abovereferred to;

FIG. 8 is a perspective view of a paper web being drawn over the foldingboard illustrated in FIG. 7, and

FIG 9 is a plan view of a sheet metal blank which is bent to form thefolding board.

Like characters of reference designate like parts in the several views.

Referring now to the drawings, the illustrated folding apparatuscomprises, in general, folding mechanism 10 which is arranged to producetwo elongated stacks A and B of interfolded tissues, a folding device 11for longitudinally folding a web 12 of tissue, a pair of web guides 13and 14, and a folding device 15 which is constructed to interfold theweb 12 with adjacent folds of the tissue stacks A and B.

The tissue stack A is made up of a web of paper tissue which is foldedalong a longitudinal center line so as to have folds a and b, a secondweb which is folded on a longitudinal center line to have web folds cand d, a third web folded in the same manner to have web folds e and f,a fourth web likewise folded to have web folds g and h, and a pluralityof other webs folded in the same manner as the four webs specificallymentioned having folds a to h. As will be observed, the webs arelongitudinally interfolded with the fold c of the second web between thefolds a and b of the first web, with the fold b of the first web and thefold e of the third web between the folds c and d of the second web, andwith the folds d and g of'the second and fourth webs between the folds eand f of the third web, and each lower fold of each of the other foldedwebs in the stack A is likewise disposed beneath the upper fold of thenext lowermost web in the stack. The stack A is a stack of webs ofindefinite length, and it is contemplated that such a stack may be cutinto segments or perhaps 10 inches in length. The resulting 10 inchsubstacks so formed may be packaged in cartons with a dispensing slot atthe top, and due to the fact that the webs are interfolded as justdescribed, the removal of the top web in the stack results in the topfold of the next lower tissue in the stack being partially pulledthrough the slot so that it may be easily grasped by the user.

The stack of tissues B is formed in the same manner as the stack A. Theuppermost web of the stack B has upper and lower web folds l and m, thenext lower web in the stack has web folds n and 0; the third web in thestack has web folds p and q; and, in the case of each tissue, thelowermost fold is disposed below the uppermost fold of the nextsucceeding tissue in the stack to provide the interfolding previouslydescribed.

Each of the stacks A and B of interfolded tissues may be formed in anysuitable manner, such as, for example, by a series of the foldingdevices disclosed in Patent 2,642,279, issued June 16, 1953, to OliverE. Teall, or a series of the folding devices of the type disclosed in aco-pending application of Harold V. Rutkus and Charles J. Greiner,Serial No. 837,977, filed September 3, 1959, on Paper Folding Machineand Method (now Patent No. 3,066,932, issued December 4, 1962). Suchseries of folding devices could, of course, be utilized for forming anultimate, relatively high, stack of tissues consisting of the stacks Aand B combined; however, since a folding device is required for each ofthe Webs, a very long series of folding devices would be required. Inorder to form the stacks A and B separately as is proposed herein, twoseries of such folding devices would be required with only half of thetotal number of folding devices being utilized for each of the stacks Aand B and with one half of the total number of folding devices beingdisposed on two levels, a lower level for the stack B and a higher level3 for the stack A, thus halving the total length of the machine.

When two such upper and lower series of folding devices are utilized,however, the separate stacks A and B result, and if it is desired thatsegments of the stacks A and B be packed in the same carton one abovethe other, it is also desirable that the two stacks A and B beinterfolded with each other, so that tissues may be withdrawn from thecarton without interruption between the uppermost and lowermostsubstacks A and B in the carton. The folding device 15, as will be madehereinafter apparent, functions to connect and .interfold together thetwo tissue stacks A and B before any severance into segments of thestacks A and B takes place.

Any suitable type of folding device may be utilized for folding the web12 lengthvv'ise along its longitudinal center line. The folding device11 that is illustrated is of the type disclosed in the aforementionedRutkus and Greiner patent application, Serial No. 837,977, andconstitutes a sheet metal folding board having plane portions 11a, 11band 110 which have folding edges 33rd and lie between them and whichhave terminal folding edges 11; and Fig. The plane portion tile extendssubstantially horizonta ly; the plane portion lla extends upwardly andobliquely with respect to the portion 110; and the portion 11b extendsobliquely with respect to both portions 11a and 110.

The folding device 11 is suitably mounted with respect to a horizontaltable ll by means of standards 17 and a bar 13 which extends between thestandards and to which is fixed the upper end of the plane portion 11a.The other end of the folding device is supported with respect to thetable 16 by means of a stud 19. A roller 2t? is disposed between thestandards 17, and the web 12 passes over the roller from a roll 21 ontothe plane portion 11a at the upper end of the plane portion 11a. The webis so disposed laterally of the folding device 11 that the longitudinalcenter line of the web passes beneath the point joining the threefolding edges 11g, He and 11 and the half of the web 12 on one side ofthe longitudinal center line passes directly downwardly on the surface11a and passes under the folding edge 11g and over the horizontal planeportion 11c producing a top fold 12a. The other half of the web travelsdownwardly on the surface 11a, over the folding edge did, over the planesurface 115, under the folding edge lle beneath the horizontal planesurface 110, and over and around the folding edge Ill being therebyfolded through 180 degrees to produce an underfold 1212.

A roller 22 is supported by standards 23 fixed to the table 16 andfunctions to hold the upper and lower folds 12a and 12b of the web 12 incontact and to crease the web 12 along its longitudinal center line.

The folding device comprises an upper plane portion 15a and a lowerplane portion 1511 joined at one edge 150. The folding device 15 isrectangular except for diagonally extending folding edges d and 15s onthe ends of the plane portions 15a and 155, respectively. The foldingdevice 15 is formed from a fiat sheet metal blank 24 illustrated in FIG.9, which is bent or folded back upon itself along a longitudinal centerline as to thereby form the flat portions 15a and 155 connected at theedge 115C.

The folding device 15 is mounted with respect to the table 16 by meansof a mounting strip 26 adjustably fixed to the table by means of studs27. A support plate 28 is pivotally mounted with respect to the strip26, and an upper clamping plate 29 is fixed with respect to the plate 28 by means of screws 3t A key strip 31 is disposed between the parts 28and 29 and is clamped between them by means of the screws The strip 31has a relatively thin terminal portion 32 disposed between the flatportions 15a and 15b of the folding device 15, and the portions 15a, 15band 32 are suitably fixed 4 together to support the folding the plate 28and the table 16.

The web guides 13 and 14 are fixed with respect to the table in: bymeans of screws 33, and a spacer plate 3-6- is provided between theparts 13 and 14 for holding them properly spaced respectively below andabove the plane portions 15b and 15a of the folding device 15, asillustrated in FIG. 3.

The web stacks A and B travel in vertical alignment from the foldingdevice 1 3 along a path 35 in the direction of the arrow The stacks Aand B may be drawn along as continuous l ngths by any suitablemechanism, such as by uppx and lower driven rolls 3'7 and 33. The upperand lower edges 1542 of the folding device 15 extend diagonally acrossthe path 35 with the outer tips of the device being located downstreamin the path of the web stacks A B, and the web guides 13 and also extendacross the path 35 as shown in PEG. 1. The web guides 13 and are sodisposed and spaced with respect to each other that they provide aslight separation of the web stacks A and B, the web guide 14 beingdisposed in the stack A just within the lowermost web fold a of thestack A, and the web guide 13 being disposed within the stack B justunderneath the uppermost web fold I of the stack B, as illustrated inFIG. 6. The web 12 has been folded by the folding device fit along alongitudinal center line with the upper and lower folds T220 and aspreviously described, and the folded web 12 passes over the foldingdevice 15 with its fold in contact with the close folded edge lie of thedevice 15. The upper fold 12a passes around the edge of the foldingdevice 15 through degrees, and the top fold 12a then is in alignmentwith and passes along the path 35. At the same time, the bottom fold 12bpasses upwardly and around the lower edge 15c of the folding devices 15through 180 degrees and travels along with the upper fold 12a in thepath 35. The manner in which the web folds 12a and 12b turn in passingover the folding edges l5a' and life is illustrated in PEG. 8. Both ofthe external web folds a and l of the web stacks A and B are trained topass between the folding edges 15d and -S'e of the folding device 15;and, therefore, since the web folds 12a and 121) are in contact with theinner surfaces of the folding device 15, the web folds Til-a and 1219are thereby inserted respectively between the web folds c and a andbetween the Web folds l and n, so that the web 12 in effect tiestogether the two stacks A and B and continues the interfolding patternfrom the lowest tissue of the stack B to the uppermost tissue of thestack A. When the combined stack consisting of the parts A and B issevered into segments, the Web 12 thus assures that the dispensingaction due to the interfolding, with each uppermost web drawing the webjust below it through the slot in the carton, shall be complete throughthe combined stack AB.

it will be observed from FIG. 9 that the folding edges 15d and 15a inthe sheet metal blank extend at angles of 45 degrees with respect to thelongitudinal center line 2-5 of the blank prior to folding of the blankinto its operative form. The edge 15c and, therefore, the folding device15 as a whole, as ill be observed from FIG. 1, extend at an angle of 90degrees with respect to the path of travel of the stacks A and Bindicated by the arrow 3-6, and the web 12 is fed between the web stacksA and B as above described at this 96 degree angle with respect to thepath of travel of stacks A and B. The folding edges 15d and 15s extenddiagonally across and move particularly at an angle that bisects theangle at which the web 12 initially travels with respect to the path oftravel of the stacks A and 3, namely at 45 degrees with respect to thepath of travel of the web stacks A and B indicated by the arrow 36, sothat the web 12 as it is interfolded with the stacks A and B does notwrinkle and is not stretched more along any particular longitudinalfiber than along any other.

device 15 with respect to The folding device advantageously turns afolded web from one direction to another and due to its spacedoverlapping top and bottom plane portions 15a and 151) allows a web foldor web folds of previously folded webs to pass between these portions sothat the web passing over and being changed in direction by the foldingdevice is interfolded with the folds of the previously folded webs. Itwill be apparent that although I have disclosed only a single foldingdevice 15 extending at right angles with respect to the path of travel35, a plurality of such folding devices 15 may be utilized in connectionwith a stack of tissues traveling along the path 35, each of the foldingdevices 15 being so disposed to add an additional web to the stacktraveling along the path, such as to the bottom or top of the stack. Forsuch operation, the top or bottom fold of the stack simply passesbetween the plane portions 15a or 1512 so as to have a fold of the web12 passing over the folding device 15 inserted beneath the external foldof the stack traveling along the path 35. if the folding device 15 isused to add an additional web to the top or bottom of a previouslyinterfolded stack of webs, the folded webs would appear the same asshown in FIG. 6, but with all webs of either the stack A or stack Babsent.

I wish it to be understood that the invention is not to be limited tothe specific constructions and arrangements shown and described, exceptonly insofar as the claims may be so limited, as it will be apparent tothose skilled in the art that changes may be made without departing fromthe principles of the invention.

What is claimed is:

1. In apparatus for folding flexible sheet material webs, thecombination of mechanism for interfolding a plurality of sheet materialwebs to provide a stack of interfolded webs with a lower fold of eachupper web underlying the upper fold of a web below it in the stack,means for drawing said webs in a continuous length along a predeterminedpath, means for longitudinally folding an additional sheet material webso that it has two overlapping folds, and a folding device forinterfolding said additional web as so folded with one of the externalwebs of the stack of interfolded webs, said device comprising a pair ofspaced overlapping sheet material parts joined together along a sideedge of each part, each of said parts being provided with an end edgeextending diagonally with respect to the joined side edges and thedevice being so disposed that an external fold of one of the stack ofinterfolded webs travels between said end edges, said additional webbeing drawn longitudinally over said folding device with its folds incontact with said opposite parts and with its fold traveling along saidjoined side edges, and with each of the overlapping folds of saidadditional web traveling around and being folded by one of said endedges so that the additional web is longitudinally folded and passesbetween said parts and has one of its resulting folds inserted beneaththe external fold of said interfolded stack that passes between saidparts.

2. In apparatus for folding flexible sheet material webs, thecombination of mechanism for interfolding a plurality of the webs toprovide a pair of continuous aligned upper and lower stacks of the sheetmaterial with a lower fold of each upper web underlying the upper foldof each lower web in each stack providing interfolding of the webs ineach stack, means for drawing said webs in a continuous length along apredetermined path, means for longitudinally folding an additional sheetmaterial web so that it has overlapping folds, and a folding device forinterfolding said additional web with adjacent external web folds onsaid stacks, said device comprising a pair of spaced overlapping sheetmetal parts having a joint along one side edge of each part with each ofsaid parts being provided with an end edge extending from an end of saidjoint and diagonally with respect to said joint, said device being sodisposed that the adjacent external folds of said two stacks ofinterfolded webs travel between said end edges, said additional webtraveling longitudinally of said folding device with its folds incontact with said overlapping parts and with its fold traveling alongsaid joint, each of said overlapping folds of said additional web beingdrawn around and being folded by one of said end edges so that theadditional web is longitudinally folded and passes between said partsand has one of its resulting folds inserted above the lowermost fold ofthe upper stack and has its other fold inserted beneath the uppermostfold of said lower stack as said stacks of webs travel in said path.

3. In a method for interfolding webs of flexible sheet material, thesteps which comprise, providing a continuous stack of interfolded sheetmaterial webs in which a lower fold of each upper web underlies theupper fold of a lower web in the stack, and drawing said stack in apredetermined path, longitudinally folding an additional web to have apair of overlapping folds and drawing the web in a path extending at anangle to said first named path, and drawing the folds of said additionalweb over a pair of spaced aligned straight edges which are disposeddiagonally across said first named predetermined path with an externalfold of said stack of webs being passed between said straight edgeswhereby said additional web has its overlapping folds changed in direction to travel in said first named path and one of the overlapping foldsof said additional web is disposed between the exterior fold of saidstack and the remainder of the stack as the stack travels in its saidpath.

4. In a method for interfolding webs of flexible sheet material, thesteps which comprise, providing a pair of aligned upper and lowerinterfolded continuous stacks of sheet material Webs wherein the lowerfold of each upper web underlies the upper fold of each immediatelyadjacent lower web in the stack, drawing said stacks along apredetermined path, longitudially folding an additional web so that ithas a pair of overlapping folds and drawing the additional web in asecond predetermined path that is at an angle with respect to said firstpredetermined path, passing the overlapping folds of said additional webaround a pair of spaced aligned straight edges, said straight edgeslying diagonally across said first predetermined path with one end ofeach of said straight edges being in alignment with the fold of saidadditional Web and the edge of said first path and the other ends ofsaid straight edges extending in the direction of movement of saidcontinuous stacks and at an angle from said fold that is equal to halfthe angle between said first and second paths, adjacent exterior foldsof said upper and lower stacks being passed between said straight edgesand the folds of said additional web being drawn across said straightedges so that the straight edges turn the latter folds so that theytravel in said first path to dispose each of the overlapping folds ofsaid additional web between the exterior fold of one of said stacks andthe remainder of the stack.

References Cited in the file of this patent UNITED STATES PATENTS2,278,043 Sailer Mar. 31, 1942

1. IN APPARATUS FOR FOLDING FLEXIBLE SHEET MATERIAL WEBS, THECOMBINATION OF MECHANISM FOR INTERFOLDING A PLURALITY OF SHEET MATERIALWEBS TO PROVIDE A STACK OF INTERFOLDED WEBS WITH A LOWER FOLD OF EACHUPPER WEB UNDERLYING THE UPPER FOLD OF A WEB BELOW IT IN THE STACK,MEANS FOR DRAWING SAID WEBS IN A CONTINUOUS LENGTH ALONG A PREDETERMINEDPATH, MEANS FOR LONGITUDINALLY FOLDING AN ADDITIONAL SHEET MATERIAL WEBSO THAT IT HAS TWO OVERLAPPING FOLDS, AND A FOLDING DEVICE FORINTERFOLDING SAID ADDITIONAL WEB AS SO FOLDED WITH ONE OF THE EXTERNALWEBS OF THE STACK OF INTERFOLDED WEBS, SAID DEVICE COMPRISING A PAIR OFSPACED OVERLAPPING SHEET MATERIAL PARTS JOINED TOGETHER ALONG A SIDEEDGE OF EACH PART, EACH OF SAID PARTS BEING PROVIDED WITH AN END EDGEEXTENDING DIAGONALLY WITH RESPECT TO THE JOINED SIDE EDGES AND THEDEVICE BEING SO DISPOSED THAT AN EXTERNAL FOLD OF ONE OF THE STACK OFINTERFOLDED WEBS TRAVELS BETWEEN SAID END EDGES, SAID ADDITIONAL WEBBEING DRAWN LONGITUDINALLY OVER SAID FOLDING DEVICE WITH ITS FOLDS INCONTACT WITH SAID OPPOSITE PARTS AND WITH ITS FOLD TRAVELING ALONG SAIDJOINED SIDE EDGES, AND WITH EACH OF THE OVERLAPPING FOLDS OF SAIDADDITIONAL WEB TRAVELING AROUND AND BEING FOLDED BY ONE OF SAID ENDEDGES SO THAT THE ADDITIONAL WEB IS LONGITUDINALLY FOLDED AND PASSESBETWEEN SAID PARTS AND HAS ONE OF ITS RESULTING FOLDS INSERTED BENEATHTHE EXTERNAL FOLD OF SAID INTERFOLDED STACK THAT PASSES BETWEEN SAIDPARTS.
 3. IN A METHOD FOR INTERFOLDING WEBS OF FLEXIBLE SHEET MATERIAL,THE STEPS WHICH COMPRISE, PROVIDING A CONTINUOUS STACK OF INTERFOLDEDSHEET MATERIAL WEBS IN WHICH A LOWER FOLD OF EACH UPPER WEB UNDERLIESTHE UPPER FOLD OF A LOWER WEB IN THE STACK, AND DRAWING SAID STACK IN APREDETERMINED PATH, LONGITUDINALLY FOLDING AN ADDITIONAL WEB TO HAVE APAIR OF OVERLAPPING FOLDS AND DRAWING THE WEB IN A PATH EXTENDING AT ANANGLE TO SAID FIRST NAMED PATH, AND DRAWING THE FOLDS OF SAID ADDITIONALWEB OVER A PAIR OF SPACED ALIGNED STRAIGHT EDGES WHICH ARE DISPOSEDDIAGONALLY ACROSS SAID FIRST NAMED PREDETERMINED PATH WITH AN EXTERNALFOLD OF SAID STACK OF WEBS BEING PASSED BETWEEN SAID STRAIGHT EDGESWHEREBY SAID ADDITIONAL WEB HAS ITS OVERLAPPING FOLDS CHANGED INDIRECTION TO TRAVEL IN SAID FIRST NAMED PATH AND ONE OF THE OVERLAPPINGFOLDS OF SAID ADDITIONAL WEB IS DISPOSED BETWEEN THE EXTERIOR FOLD OFSAID STACK AND THE REMAINDER OF THE STACK AS THE STACK TRAVELS IN ITSSAID PATH.